Cleaning of hard surfaces, such as floors (vinyl, linoleum, tile, cement), countertops, showers, etc. is well known in the art. Cleaning may be accomplished using cellulosic paper towels and non-woven sheets, as are well known in the art. Nonwoven sheets may be made according to commonly assigned U.S. Pat. Nos. 6,936,330 and/or 6,797,357. Cellulosic paper towels may be made according to commonly assigned U.S. Pat. No. 4,191,609 and/or 4,637,859.
Such sheets have been removably attached to manual implements. The implements increase reach, and improve ergonomics. For example, when the hard surface to be cleaned is a floor, the implement allows the user to clean from a standing position, improving comfort over cleaning from a crouched position or on the knees. Manual implements may be made according to commonly assigned U.S. Pat. Nos. 6,305,046 and/or D588,770.
One problem encountered when cleaning floors is that a user can encounter tacky soils, which tend to stick to the floor, and/or encounter a variety of fine soils, such as dust, granular soils, dried food debris, plants, mud, etc. which tend to stick to the floor less.
To improve cleaning of soluble and tacky stains, wetted and wettable floor sheets have been used. Pre-wetted floor sheets include those having APG polymers, as disclosed in commonly assigned U.S. Pat. No. 6,716,805. Wettable floor sheets have been used with the commercially available Swiffer WetJet® device. This device sprays cleaning solution onto the floor from a replaceable reservoir, as described in commonly assigned U.S. Pat. No. 8,186,898. Cleaning solution chemistry and a reservoir therefor may be made according to commonly assigned U.S. Pat. No. 6,386,392. Floor sheets which absorb cleaning solution from the floor may be made according to commonly assigned U.S. Pat. Nos. 5,960,508, 6,101,661 and/or 7,144,173.
But these attempts do not always sufficiently clean the entire range of soils encountered, particularly large particles, such as cereal and chunks of mud from the floor. To overcome the problem of loose, large particle cleaning, rotatable beater bars have been utilized, as disclosed in U.S. Pat. No. 9,783, reissued Jun. 28, 1881; 306,008 issued Sep. 30, 1884; 329,257 issued Oct. 27, 1885; U.S. Pat. No. 4,654,927 issued Apr. 7, 1987; U.S. Pat. No. 7,134,161 issued Nov. 14, 2006. The beater bars in these teachings are driven by the wheels. Particularly, each of these references teaches plural wheels contacting the floor to be cleaned. The wheels drive the beater bar, obviating the need for a separate electric motor. Electric motors add cost and weight to the device. Split beater bars have also been used, as shown in 2005/0055792 and U.S. Pat. No. 7,134,161.
Many mechanical sweepers use beater bars comprising nylon bristles. Bristles may also be used on carpets, where bristles can help loosen hair. Bristles can be prone to hair/lint/thread wrapping which quickly degrades performance. Since mechanical sweepers rely on momentum for pick-up, contaminated bristles reduce cleaning capability. Additionally, bristles can separate, requiring higher rotational speed to reduce bristle separation, and minimize particles passing through the bristles. To further reduce bristle separation, bristles are usually designed to not contact the sweeper housing or other items which may deflect the bristles. The Leifheit sweeper attempts to overcome this problem, using rubber bristles instead nylon. But even these bristles are prone to contamination and bristle to bristle separation.
Powered devices may have a beater bar which is battery or AC line powered to aide in picking up soil. These devices have higher rotational speeds and are more effective than mechanically driven beater bars. But powered devices still have problems with contamination and degradation in performance from lint/hair/thread accumulation.
Devices which also use a disposable sheet to assist in cleaning are known as illustrated by U.S. Pat. No. 7,013,528; 2009/0077761; U.S. Pat. No. 7,346,428 and commonly assigned U.S. Pat. No. 7,676,877. Use of such a disposable sheet can be improved, by adding suction, as disclosed in U.S. Pat. Nos. 7,137,169 and 7,293,322.
But navigation of these prior art devices can be tricky. The plural wheels in the prior art provide for good linear tracking and stability, but compromise maneuverability.
To assist in maneuverability, omni-directional wheels have been proposed, as set forth in US 2008/0018167; 2010/0187779; 2010/0243342; U.S. Pat. Nos. 3,789,947; 4,224,753 and 7,318,628. But these omni-wheels are expensive, leading to plural wheel attempts as shown in US 2009/0077764 and 2011/0126367.
Handles which are not straight have also been proposed to improve ergonomics, as shown in 2011/0219557 and 2009/0223007. But curved handles add complexity in manufacturing, and may not be the correct geometry.
Thus, the problem of cleaning a floor with a device which has a mechanically driven beater bar for large particles and a disposable floor sheet for small particles persists.